用於Junit測試的換行字符串

Question

要比較JUnit測試中的多行文本結果，我經常需要從文本表示 轉換爲Java代碼，該代碼使用多行文本初始化字符串。

E.g.如果測試應該檢查包含XML字符串：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
<Customer> 
    <id>100</id> 
    <name>John Doe</name> 
    <orders> 
     <Order> 
      <address>100 main street, smalltown, pa</address> 
      <orderid>1100</orderid> 
     </Order> 
     <Order> 
      <address>5 broadway, ny, ny</address> 
      <orderid>1200</orderid> 
     </Order> 
    </orders> 
</Customer> 

我想用一個工具/發電機採用上面的輸入，並得到以下結果：

String expected =""; 
    expected+="<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n"; 
expected+="<Customer>\n"; 
expected+=" <id>100</id>\n"; 
expected+=" <name>John Doe</name>\n"; 
expected+=" <orders>\n"; 
expected+="  <Order>\n"; 
expected+="   <address>100 main street, smalltown, pa</address>\n"; 
expected+="   <orderid>1100</orderid>\n"; 
expected+="  </Order>\n"; 
expected+="  <Order>\n"; 
expected+="   <address>5 broadway, ny, ny</address>\n"; 
expected+="   <orderid>1200</orderid>\n"; 
expected+="  </Order>\n"; 
expected+=" </orders>\n"; 
expected+="</Customer>\n"; 

和/或

// Create test file 
    java.io.PrintWriter srcWriter = new java.io.PrintWriter(new java.io.FileOutputStream(testFile)); 
    srcWriter.println("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n"); 
    srcWriter.println("<Customer>\n"); 
    srcWriter.println(" <id>100</id>\n"); 
    srcWriter.println(" <name>John Doe</name>\n"); 
    srcWriter.println(" <orders>\n"); 
    srcWriter.println("  <Order>\n"); 
    srcWriter.println("   <address>100 main street, smalltown, pa</address>\n"); 
    srcWriter.println("   <orderid>1100</orderid>\n"); 
    srcWriter.println("  </Order>\n"); 
    srcWriter.println("  <Order>\n"); 
    srcWriter.println("   <address>5 broadway, ny, ny</address>\n"); 
    srcWriter.println("   <orderid>1200</orderid>\n"); 
    srcWriter.println("  </Order>\n"); 
    srcWriter.println(" </orders>\n"); 
    srcWriter.println("</Customer>\n"); 
    srcWriter.close(); 
    // PrintWriter never throws Exceptions, one must check the error state manually 
    // 
    if (srcWriter.checkError()) 
    { 
     throw new IOException("can not write " + testFile); 
    } 

什麼是開發工具/ eclipse實用程序或插件來實現這一目標？

• 需要從文件中多輸入文本（在IDE或命令行）
• 逃逸引號和反斜線
• 轉換成Java代碼初始化字符串文字和/或將執行文件建立在Java代碼中，而不需要額外的文件資源
• 輸出結果，以新的文件和/或控制檯或直接進入編輯器在編譯時使用

輸出文件（如果有的話）不應隨編譯結果一起發貨。在文件模式下，應該從java代碼中的字符串文字重新創建輸入文件的等效項。

Answer 1

假設您從其他源複製多行文本，並且您正在使用Eclipse，它可以自動將文本轉換爲多行String文字。

在我的版本，使其在Windows - >首選項 - >爪哇 - >編輯 - >鍵入 - >粘貼到文本

然後，如果你輸入一個字符串時逃生文本

String expected = " 

和複製一些文字像

blah 
blah 
blah 
blah 
blah 

，然後再粘貼的字符串，Eclipse將創建：

String expected = "blah\n" + 
"blah\n" + 
"blah\n" + 
"blah\n" + 
"blah" 

就我個人而言，如果Java有一個與Perl的HERE文檔相當的多行代碼，那就好了。

Answer 2

爲什麼不把XML存儲在單獨的文件中並使用Apache Commons將它讀入字符串？

String fileName = "path/to/your/file"; 
String fileText = FileUtils.readFileToString(new File(fileName)); 

的文件實用程序見本 - https://commons.apache.org/io/api-release/org/apache/commons/io/FileUtils.html

Answer 3

對我來說，這看起來像一個失敗。基本上，你想測試一個漂亮的打印XML與OS特定的換行符。

難道你不能簡單地寫一些簡單的Visitor模式穿越結果和預期的XML來驗證一切是否如預期的那樣？通過這種方式，您還可以避免無效預期和生成XML的問題。

另外，想象一下，如果命名空間聲明按順序變化或者屬性按順序變化：XML在語義上等同，但在語法上不同。應該如何處理？這是一個失敗的測試？在我看來，這是一個通行證。

Answer 4

對於非Eclipse用戶下面的腳本解決方案可能會有所幫助：

#!/bin/bash 
# 
# Copyright (C) 2012 BITPlan GmbH (http://www.bitplan.com) 
# 
# Author: Wolfgang Fahl 
# 
# 
# Licensed under the Apache License, Version 2.0 (the "License"); 
# you may not use this file except in compliance with the License. 
# You may obtain a copy of the License at 
# 
#  http://www.apache.org/licenses/LICENSE-2.0 
# 
# Unless required by applicable law or agreed to in writing, software 
# distributed under the License is distributed on an "AS IS" BASIS, 
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
# See the License for the specific language governing permissions and 
# limitations under the License. 


# 
# wrap code for use in JUnit Test cases 
# 
wrapJUnit() { 
    file=$1 
    mode=$2 
    echo "wrapping $file with mode $mode" 
    cat $file | gawk -v mode="$mode" ' 

# check mode and add header if mode is file 
BEGIN { 
    if (mode=="file") { 
     print " // Create test file" 
     print " java.io.PrintWriter srcWriter = new java.io.PrintWriter(new java.io.FileOutputStream(testFile));" 
    } 
} 
# work on each line 
{ 
    line=$0 
    # replace a single \ with \\ 
    gsub("\\","\\\\",line) 
    # replace a quote with \ quote 
    gsub("\"","\\\"",line) 
    # output the modified line 
    if (mode=="file") { 
     print " srcWriter.println(\"" line "\\n\");" 
    } else { 
     if (more++) { 
      print " expected+=\"" line "\\n\";" 
     } else { 
      print " expected =\"" line "\\n\";" 
     } 
    } 
} 

END { 
    if (mode=="file") { 
     print " srcWriter.close();" 
     print " // PrintWriter never throws Exceptions, one must check the error state manually" 
     print " //" 
     print " if (srcWriter.checkError())" 
     print " {" 
     print "  throw new IOException(\"can not write \" + testFile);" 
     print " } " 
    } 
} 

' > $1.wrap 
cat $1.wrap 
} 

# 
# 
# show usage 
# 
usage() { 
    echo "usage: wrapcode inputfile [simple]" 
    echo " will take the text and prepare it for JUnit usage as a string"; 
    exit 1 
} 

# 
# check number of command line parameters 
# 
if [ $# -lt 1 ] 
then 
    usage 
fi 

file=$1 

if [ $# -lt 2 ] 
then 
    wrapJUnit $file file 
else 
    wrapJUnit $file string 
fi